From: David Hildenbrand <david@redhat.com>
To: Wei Yang <richard.weiyang@gmail.com>,
akpm@linux-foundation.org, lorenzo.stoakes@oracle.com,
ziy@nvidia.com, baolin.wang@linux.alibaba.com,
Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com,
dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev,
xu.xin16@zte.com.cn, chengming.zhou@linux.dev
Cc: linux-mm@kvack.org, Kiryl Shutsemau <kirill@shutemov.name>,
Dan Carpenter <dan.carpenter@linaro.org>
Subject: Re: [Patch v3 1/2] mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL
Date: Wed, 24 Sep 2025 11:35:21 +0200 [thread overview]
Message-ID: <eb89e41b-c627-4a07-8388-8a3074ce0620@redhat.com> (raw)
In-Reply-To: <20250924004854.29889-2-richard.weiyang@gmail.com>
On 24.09.25 02:48, Wei Yang wrote:
> Patch series "mm_slot: fix the usage of mm_slot_entry", v2.
>
That should be dropped.
Subject: "mm/ksm: don't call mm_slot_entry() when the slot is NULL"
> When using mm_slot in ksm, there is code like:
>
> slot = mm_slot_lookup(mm_slots_hash, mm);
> mm_slot = mm_slot_entry(slot, struct ksm_mm_slot, slot);
> if (mm_slot && ..) {
> }
>
> The mm_slot_entry() won't return a valid value if slot is NULL generally.
> But currently it works since slot is the first element of struct
> ksm_mm_slot.
>
> To reduce the ambiguity and make it robust, access mm_slot_entry() when
> slot is !NULL.
"... only call mm_slot_entry() when we have a valid slot."
--
Cheers
David / dhildenb
next prev parent reply other threads:[~2025-09-24 9:35 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-24 0:48 [Patch v3 0/2] mm_slot: fix the usage of mm_slot_entry Wei Yang
2025-09-24 0:48 ` [Patch v3 1/2] mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL Wei Yang
2025-09-24 2:19 ` Chengming Zhou
2025-09-24 9:35 ` Kiryl Shutsemau
2025-09-24 9:40 ` David Hildenbrand
2025-09-24 10:06 ` Kiryl Shutsemau
2025-09-24 10:09 ` David Hildenbrand
2025-09-24 10:15 ` Kiryl Shutsemau
2025-09-24 10:42 ` David Hildenbrand
2025-09-24 14:52 ` Wei Yang
2025-09-24 9:35 ` David Hildenbrand [this message]
2025-09-24 0:48 ` [Patch v3 2/2] mm/khugepaged: remove definition of struct khugepaged_mm_slot Wei Yang
2025-09-24 3:18 ` Lance Yang
2025-09-24 5:51 ` Dev Jain
2025-09-24 9:39 ` David Hildenbrand
2025-09-24 14:59 ` Wei Yang
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